SYDNEY - Vatican finance chief George Pell is being investigated by Australian police over child sexual abuse allegations, a report by the national broadcaster said Wednesday, as the leading Catholic cleric denounced the claims as "totally untrue".

The new allegations against Pell being probed by police in Victoria state span two decades, the Australian Broadcasting Corporation reported. They came just months after the cardinal admitted he "mucked up" in dealing with paedophile priests in the state.

When he was the Catholic Archbishop of Sydney in 2002 Pell was accused of historic sex abuse claims but was later cleared of any wrongdoing.

The ABC said it had obtained eight police statements from complainants, witnesses and family members helping the police investigation. But the 75-year-old strongly denied the allegations in a statement to the ABC, saying "claims that he has sexually abused anyone, in any place, at any time in his life are totally untrue and completely wrong".

A Victoria police spokeswoman told AFP they would not be making any comment. Victoria police Chief Commissioner Graham Ashton said in June police were looking into allegations against Pell.

The allegations include claims from two men, now in their 40s, who said they were groped by Pell in summer 1978-79 at Eureka pool in Ballarat, where the cleric had grown up and worked.

The national Royal Commission into Institutional Responses to Child Sexual Abuse in Australia was established in 2012 after a decade of growing pressure to investigate widespread allegations of paedophilia.

The police investigation into Pell - which the ABC said has lasted more than a year and involves allegations from Ballarat, Torquay and Melbourne - is part of a wider probe into complaints that emerge from the royal commission.

The commission has spoken to almost 5,000 survivors and heard harrowing allegations of child abuse involving places of worship, orphanages, community groups and schools.

Pell previously told the commission he was not aware of offences that had occurred in Victoria, where paedophile priests abused dozens of children in the 1970s and 1980s.

He has also denied allegations raised during the commission that he tried to bribe a victim of the now-jailed paedophile priest Gerald Ridsdale - with whom he once shared church accommodation - to keep him quiet.

While consistently denying any wrongdoing, the high-flyer has admitted he "should have done more" to follow up on claims of abuse by other clergy.

Pell was ordained in Rome in 1966 before returning to Australia in 1971 and rising to become the nation's top Catholic official.

He left for the Vatican in 2014 after being hand-picked by Pope Francis to make the church's finances more transparent.

Francis has approved the creation of an internal church tribunal to punish bishops who cover up sex abuse by priests, but networks of abuse survivors are sceptical that much will change.

Other countries where alleged or confirmed cases of sexual abuse have come to light include Austria, Belgium, Canada, Germany, Ireland, Mexico, the Netherlands, Poland and the United States.